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Making Chocolate More Nutritious

<p>Earlier this week, I blogged about the many health benefits of chocolate, including new research supporting its role in increase energy, exercise stamina and heart health in elderly adults. A challenge for chocolate makers, however, is maintaining its antioxidant content&#0151;during the roasting process, some of the healthful polyphenols, aka antioxidants, are lost. New research presented at the 249th National Meeting &amp; Exposition of the American Chemical Society (ACS) found a way to make the treat even more nutritious&#0151;and sweeter.</p>

Mar 27, 2015

Earlier this week, I blogged about the many health benefits of chocolate, including new research supporting its role in increasing energy, exercise stamina and heart health in elderly adults. A challenge for chocolate makers, however, is maintaining its antioxidant content—during the roasting process, some of the healthful polyphenols, aka antioxidants, are lost. New research presented at the 249th National Meeting & Exposition of the American Chemical Society (ACS) found a way to make the treat even more nutritious—and sweeter.

Cocoa undergoes several steps before it takes shape as a candy bar. Workers cut down pods from cocoa trees, then split open the pods to remove the white or purple cocoa beans. They are fermented in banana-lined baskets for a few days and then set out to dry in the sun. Roasting, the next step, brings out the flavor. But as stated above, some of the health benefits are lost during this process, so the researchers wanted to figure out a way to retain as much of the polyphenols and good flavors as possible.

"We decided to add a pod-storage step before the beans were even fermented to see whether that would have an effect on the polyphenol content," said Emmanuel Ohene Afoakwa, Ph.D., University of Ghana. "This is not traditionally done, and this is what makes our research fundamentally different. It's also not known how roasting affects polyphenol content."

Afoakwa's team divided 300 pods into four groups that were either not stored at all or stored for three, seven or 10 days before processing. This technique is called "pulp preconditioning." After each storage period passed, fermentation and drying were done as usual. He reported the seven-day storage resulted in the highest antioxidant activity after roasting.

To assess the effects of roasting, the researchers took samples from each of the storage groups and roasted them at the same temperature for different times. The current process is to roast the beans for 10 to 20 minutes at 248° to 266° F. Afoakwa's team adjusted this to 45 minutes at 242° F and discovered this slower roasting at a lower temperature increased the antioxidant activity compared to beans roasted with the conventional method.

In addition, the beans that were stored and then roasted for 45 minutes had more polyphenols and higher antioxidant activity than beans whose pods were not stored prior to fermentation, Afoakwa said. He explained pulp preconditioning likely allowed the sweet pulp surrounding the beans inside the pod to alter the biochemical and physical constituents of the beans before the fermentation.

"This aided the fermentation processes and enhanced antioxidant capacity of the beans, as well as the flavor," he said, adding the new technique would be particularly useful for countries in Southeast Asia and Latin America where cocoa beans produce a chocolate with a less intense chocolate flavor and have reduced antioxidant activity.